Multiple system



L. NEMIROVSKY MULTIPLE SYSTEM Jan. 2, 1934.

Filed Feb. 7, 1950 Transmitter Transm 1'! far Patented Jan. 2, 1934 MULTIPLE SYSTEM Leon Nemirovsky, Paris, France, assignor to Antoine Belloy, Paris, France Germany February 11, 1929 Application February 7, 1930, Serial No. 426,662, 7 and in 1 Claim.

This invention relates to a method and to a device for transmitting telephonic and telegraphic messages, said method and device bein calculated to increase considerably the efficiency 5 of existing installations by permitting several conversations to be conducted simultaneously over ordinary telephone wires or by wireless.

My device is very simple and, since the rapidity of transmissions is adjustable and can be made extremely great, I am enabled to cause messages to be sent in a manner that renders them unintelligible for unauthorized third parties thereby rendering futile any attempt at intercepting messages so sent over wires or by wireless.

This invention utilizes oscillations produced in the microphone by the action of sounds or talk so as to impart them to a mobile conductor. An

electromagnetic device, moving in the direction opposite to the movement ofsaid conductor, collects, on a predetermined portion of itstravel, such oscillations and transmits them over wires or by wireless to another electromagnetic device which, during a predetermined portion of its travel, imparts the transmitted oscillations to a wire moving in the opposite direction. The latter wire transmits these oscillations to a receiver (telephone, telegraph, etc.) which transforms them into sounds or into signals.

In order to make my invention more clearly understood I have illustrated, as an example, an

embodiment thereof in and by a drawing appended hereto which illustrates diagrammatically an installation set up in accordance therewith.

Each microphone circuit includes microphone M, battery P and electro-magnet E1 together with the necessary wiring.

The sound waves that influence the microphone of set A, produce current oscillations in its circuit, whereby the magnetism of electro-magnet E1 is modified. Such modifications are registered by the steel wire L1 which is moving at a constant speed near the poles of electro-magnet E1. Wire L1 receives, therefore, magnetic currents variable and proportional to the magnetic changes of electro-magnet E1. Farther on wire L1 passes in front of the poles of a second electro-magnet E2, inducing in the coils thereof currents which,

amplified in amplifier R1, take action on the electro-magnet E3 of set or station B. Electro-magnet E3 transmits the variable magnetic currents to wire L2 which causes current'oscillations in the coils of electro-magnet E4. Those currents, amplified in amplifier R1, take action on the telephone receiver T, which will produce the sound waves registered -by microphone M.

According to the invention the electro-magnets' E: and E3 are constituted by mobile parts rotated at a constant speed which is adjustable. The steel wire L1 of station A is moved, as above explained, at a constant speed in front of the poles of electro-magnet E1 and continues to travel along an arc of a circle K" whereon, between fixed points a and b, takes place the influence between wire L1 and rotary electro-magnet E2. The latter is rotated in a direction reverse to the travel of wire L1 and its speed is so adjusted that it will travel round the whole circumference of a circle in the same time as any one point of wire L1 will travel round arc K. Under such conditions, no point of wire L1 will pass in front of the poles of electro-magnet E2 without transmitting to the coils thereof currents corresponding to the variable magnetic currents of wire L1.

The characteristic feature ofthe transmission consists of the fact that oscillations are transmitted in a condensed state and by impulses and not in a constant manner.

In order to reproduce at station B the sound waves registered by the microphone of station A,

I use a receiving device analogous to the sending so device but adapted to repeat the operation in reversed order. The current oscillations transmitted from A to B over wires D1 and D2 or on waves arrive into electro-magnet E3 which is timed to rotate perfectly synchronous with electro-magnet 35 E2. Said oscillations will cause magnetic changes which, through wire L2, will take action on electro-magnet E4. The current oscillations, produced in the latters coils and amplified in amplifler R2, will take action on receiver T which will transform them into sounds. Obviously, at station B, electro-magnet E3 and wire L2 that cooperate must also be moving in opposite directions. Obviously too, the oscillations transmit ted in a condensed state from station A to station 9? B will be expanded at the latter by the reciprocal action of electro-magnet E3 and of steel wire L2 whereby their original frequency will be restored to acoustic oscillations or to signals.

The conduits that connect A with B contain current only during the period of time during which electro-magnets E11 and E3 travel round arc of circle a-b=K. Consequently, the free part of the circumference, which is equal to 360-K, can be used for installing other analogous devices the number of which will be determined by 360K KO In this manner I am enabled, if, for instance,

the feature that my invention is angleK is of 36, to install 10 wires mobile in front of electro-magnets E2 or E3, resulting, in applicable to multiplex telephony or telegraphy.

The above described devices are available, of course, for obtaining telephonic or telegraphic transmission in the reversedirection, that is to say from B to A. In this case I have but to add a return wire, when transmission is carried over wires, so that, there is a set 01' three conductor wires.

This invention is also available for secret telephony, and for this purpose, I have but to cause the rotary. electro-magnets to be rotated at such a speed that messages intercepted by unauthorized third parties will be utterly unintelligible for them.

I can also transmit messages in opposite direction by changing the direction of rotation either of the mobile wires or of electro-magnets E2 and E3, such a change having the effect of reproducing at the receiving station a telephone message or a telegraphic communication beginning by the end.

The same eifect may be obtained by altering the speed of the moving parts of the devices according to a secret scale agreed upon by any two correspondents and unknown to anybody but themselves.

Synchronous timing of the rotary electro-magnets may be achieved in a variety of ways, as, for instance, by the use of the devices usual in multiplex telegraphy for maintaining synchronous the distributors at two corresponding sta- (sonorous wheel, etc.)

It required, any number of amplifiers of any type may be intercalated at suitable places in the installation.

In order to transmit Morse or Baudot telegrams, I have but to substitute for the microphone of station A a Morse key or a mechanical apparatus and to substitute for the telephone of station b a telegraphic relay, whereby my device is rendered available for the simultaneous transmission 01 telegraphic signals and of telephone messages.

I claim:

A device for transmitting simultaneously a plurality of telephonic and telegraphic messages, comprising for each message a pair or synchronously moving steel wires arranged one at the sending and the other at the receiving station, said wires at each station being arranged in a circle, the wires at each station being moved through an arc of the circle at said station, means at the sending station for recording electric impulses magnetically on the different wires therein, an electro magnet rotating about the centre 0! each of said circles and operative to pick up and record electric impulses on the diflerent wires, a transmitting circuit including the two electro magnets and an amplifier, and receivers at the receiving station including means for picking up electric impulses from the diflerent wires.

LEON NEMIROVBKY. 

